Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
J Phys Condens Matter. 2010 Oct 13;22(40):406002. doi: 10.1088/0953-8984/22/40/406002. Epub 2010 Sep 22.
Pressure-dependent electrical resistivity and ac-calorimetry measurements on single crystals of the heavy-fermion antiferromagnet U(2)Zn(17) at pressures to 5.5 GPa reveal that the low temperature magnetic order changes above ∼3 GPa. The Neél temperature (T(N) = 9.7 K at ambient pressure) decreases slowly for pressures below 3 GPa, but above this pressure a new magnetic state develops at T(M)≈8.7 K. This magnetic phase becomes more stable with pressure increase (dT(M)/dP = 1 K GPa(-1), T(M) = 10.5 K at 5.3 GPa). The heavy-electron state in U(2)Zn(17) is robust against pressure--the electronic specific heat coefficient γ≈0.4 J mol(-1) K(-2) is nearly pressure independent for both magnetic phases. Magnetic ac-susceptibility measurements show that the pressure-induced state is not ferromagnetic.
在 5.5 GPa 的压力下，对重费米子反铁磁体 U(2)Zn(17)的单晶进行了压致电阻率和交流量热法测量，结果表明低温磁有序在约 3 GPa 以上发生变化。在压力低于 3 GPa 时，奈尔温度（T(N) = 9.7 K，常压）缓慢降低，但在该压力以上，在 T(M)≈8.7 K 处会出现新的磁态。随着压力的增加，这种磁相变得更加稳定（dT(M)/dP = 1 K GPa(-1)，T(M) = 5.3 GPa 时为 10.5 K）。U(2)Zn(17)中的重电子态对压力具有很强的抵抗力——电子比热系数γ≈0.4 J mol(-1) K(-2)对于两种磁相几乎都是压力无关的。磁交流磁化率测量表明，压致状态不是铁磁性的。
